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Closer view of the fracture separating the Pine Island Glacier from the B-46 iceberg, as seen on a flight from the IceBridge operation of November 7, 2018. Credits: NASA / Brooke Medley
NASA's IceBridge operation on Wednesday, November 7, flew over an iceberg three times larger than Manhattan. This is the first time that we see the giant iceberg, dubbed B-46 by the US National Ice Center, which separated from Pine Glacier Island in late October.
The Pine Island Glacier in West Antarctica is known to have dumped icebergs in the Amundsen Sea, but the frequency of such events appears to be on the rise. Landsat 8 Operational Field Operator (OLI) acquired this image of the new iceberg on November 7, 2018.
For comparison, the second OLI image shows the same area on September 17, 2018, before a flaw spreads rapidly across the glacier and causes icebergs to appear.
Wednesday's flight plan brought the IceBridge team over the Pine Island Glacier as part of a long-term campaign to collect year-to-year measurements of sea ice, glaciers and critical regions of the Earth's ice sheets. While the NASA DC-8 was flying according to its predetermined flight pattern, the new iceberg that had calved in late October was also visible.
On October 29, the National Ice Center, which tracks icebergs for navigation purposes, estimated the surface of B-46 at 66 square miles, although satellite images and IceBridge flight showed that the main iceberg was beginning. already to break.
Ice trays, the areas of floating ice that surround much of Antarctica, harbor icebergs in the natural process of ice formation to the sea. But scientists also closely monitor whether calving frequency changes with the time. In late 2016, IceBridge began to crack on the trunk of the Pine Island Glacier, which is approximately 22 km wide. It took a year for the fault to form fully and the iceberg named B-44 disassociated in September 2017. The crack that would become the B-46 was first noticed in late September 2018 and the iceberg broke up about a month later. Pine Island has now calved important icebergs in 2013, 2015, 2017 and 2018. Previously, the glacier experienced major calving every six years or so.
According to NASA research, Pine Island and the nearby Thwaites Glacier contribute to the sea level rise on a global scale of about one millimeter per decade, their ice flow to the sea being accelerated in recent years.
A new sea ice forms in a fault created when the iceberg B-46 is separated from the Pine Island Glacier. Credits: NASA / Kate Ramsayer
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